We first got into Letterboxing on Dartmoor, introduced by my sister and brother-in-law (Izzy and the Lizard King), and got a GPSr so we could stray further from the car and (Mrs B ) not worry about finding the car when the rain came down and all visibility lost (a common occurence on Dartmoor). Then later received an email from her giving the address of G.COM say "Looks like an interesting idea", so we tried it out and we (me especially) got hooked!